Prior to the advent of Fifth Generation (5G) standards, a user equipment (UE) of a subscriber was required to reveal its permanent identity “in the clear” over an air interface of a mobile network during a registration procedure. This permanent identity is known as a Subscription Permanent Identifier (SUPI), which in many cases is an International Mobile Subscriber Identity (IMSI) of the subscriber. Once the subscriber was authenticated, encryption was enabled and a temporary identifier was assigned to the UE for subsequent communications over the air interface.
Unfortunately, the initial openness of the permanent identity of the UE became a target for malicious actors to gain unauthorized access to the mobile network. Accordingly, for 5G networks, the 3RD Generation Partnership Project (3GPP) has mandated the concealment of identities of UEs by introducing a concealed identity referred to as a Subscription Concealed Identifier (SUCI).
Given the identity concealment and use of different identities on different interfaces of a 5G network, maintaining subscriber state in a stateless network architecture of a 5G network may be very challenging.